Congrats on your first change!
So as you'll see from this, we (certainly I) can be nit-picky, especially in your first few changes, in order to hammer in Pythonisms, style guideline stuff, and best practices. That's pretty common in the industry, so it's important not to worry about it :)

Make sure the import is listed alphabetically.

Need to keep two blank lines between these.

This is only true if running on Windows. A better comment would be something like: "If the test files are executable on the file system, nose will need the --exe argument to run them."

Blank line before the if statement.
Instead of os.getcwd(), it's best to be explicit about file paths. You also don't want to assume path separators (which is the whole reason to use os.path.join). This should look more like:
os.path.join(os.path.dirname(__file__), 'djblets', 'settings.py' ....)

We use parens for multi-line if statements. This should be more like:
if (os.path.exists(...) and
    (os.stat(...) & ...)):

Note also that you shouldn't need to cast to bool.

You have some trailing whitespace on these lines (where it highlights in red in the diff viewer).

Can you indent 'settings.py' to line up with os.path.dirname?

Ship It!